Exaggerating Species Extinction – The Sequel

In 2011 I noted a report in Nature suggesting that species extinction rates have been overestimated. A new report in Science has similar implications, suggesting that fears many species will go extinct before they are even discovered are overblown. Specifically, the study suggests many common estimates exaggerate the likely number of species and presume greater extinction rates than can be verified. The abstract for the new study, “Can We Name Earth’s Species Before They Go Extinct?” reads:

Some people despair that most species will go extinct before they are discovered. However, such worries result from overestimates of how many species may exist, beliefs that the expertise to describe species is decreasing, and alarmist estimates of extinction rates. We argue that the number of species on Earth today is 5 ± 3 million, of which 1.5 million are named. New databases show that there are more taxonomists describing species than ever before, and their number is increasing faster than the rate of species description. Conservation efforts and species survival in secondary habitats are at least delaying extinctions. Extinction rates are, however, poorly quantified, ranging from 0.01 to 1% (at most 5%) per decade. We propose practical actions to improve taxonomic productivity and associated understanding and conservation of biodiversity.

That global species extinction rates may have been exaggerated does not mean that extinction and biodiversity loss are not serious problems. I believe they are. While I am unconvinced by the arguments that a loss of biodiversity threatens humanity — largely because the available empirical evidence suggests otherwise — I believe that species extinctions impoverish the world in which we live, and support efforts to protect biodiversity, so long as they are suitably protective of property rights and individual liberty. For such efforts to succeed, it is necessary to have an accurate understanding of the problem. Overhyped fears and exaggerated claims of ecological ruin can actually frustratethe development of effective solutions.